Field of the Invention
The invention relates to a sense amplifier circuit, and more particularly to a low power consumption sense amplifier circuit suitable for a ternary content addressable memory (TCAM) device or a single-ended bit line random access memory (RAM) device.
Description of the Related Art
Conventional content addressable memories (CAMs) can provide rapid matching between a specific pattern of received data bits, commonly known as a search key or comparand, and data values stored in a content addressable memory (CAM) array. In a CAM device, a CAM array can be searched in parallel. If a match occurs between each bit of a stored data value and a corresponding bit of an applied comparand, a match indication can be generated, via a match line, to indicate that the applied comparand is stored in the CAM. Data associated with the matching CAM location can then be returned. Thus, in a CAM device, a result can be determined from finding a matching value (content), and not from an address for a value, as is typically done for a random access memory (RAM).
However, power consumption in the search operation is huge compared to the read/write operation of a RAM since all match lines have to be activated to complete the search operation.
Therefore, a novel sense amplifier circuit to reduce power consumption is required.